Freezer case including self-conforming baffles

ABSTRACT

A freezer includes a freezer compartment in which frozen items are stored and frozen. Air from the freezer compartment is drawn into a fan panel by a fan. The air is cooled in an evaporator and then returned to the freezer compartment. Flexible baffles are provided in the fan panel. During normal operation, the airflow created by the fan deflects the baffles, allowing the air to flow through the fan panel unhindered. When ice and frost forms on the evaporator, a defrost mode is initiated to melt the ice with heat generated by a heater. The fan is turned off, and the baffles drop to a straight vertical position due to gravity. The vertical baffles create resistance in the airflow and prevent the heated air and moisture generated by the heater from entering the freezer compartment and forming frost on the frozen items.

BACKGROUND OF THE INVENTION

The present invention relates generally to a freezer including flexible baffles proximate to the evaporator that are in a vertical position due to gravity during a defrost mode to prevent moisture from escaping into the freezer compartment and deflect due to the airflow created by a fan during normal operation to allow air to flow without hindrance.

Reach-in glass door freezers are commonly used in grocery stores to store and freeze frozen food in a freezer compartment. The freezer includes an evaporator that cools the air in the freezer. Warm and humid air from the freezer compartment is drawn into the evaporator by a fan. In the evaporator, the warm air from the freezer compartment exchanges heat with the exterior air, cooling the air. The cooled air is then returned to the freezer compartment.

During normal operation, moisture on the evaporator forms frost and ice, reducing the gap between the evaporator fins and increasing resistance to the airflow through the evaporator. A defrost mode is occasionally performed to melt the frost and ice formed on the evaporator fins. During the defrost mode, the fan is turned off and a heater is turned on. The heat generated by the heater melts the ice and frost on the evaporator, generating a significant amount of moisture. If the moisture enters the freezer compartment, frost can form on the frozen food and affect the appearance of the frozen food.

In prior freezers, rigid baffles are positioned proximate to the evaporator to prevent the moisture generated during the defrost mode from entering the freezer compartment. A drawback to employing fixed baffles is that they block the airflow during normal operation, causing an excessive pressure drop and misdistribution of the airflow.

Hence, there is a need in the art for freezer that employs flexible baffles to prevent moisture from entering the freezer compartment during a defrost mode, but allows unhindered airflow during normal operation, as well as overcomes the other drawbacks of the prior art.

SUMMARY OF THE INVENTION

A reach-in glass door freezer includes a freezer compartment that stores and freezes frozen items, such as food. Warm and humid air from the freezer compartment enters a fan panel through a return air grill. A fan draws the air through an evaporator for cooling. The cooled air then exits the fan panel through a rear duct and reenters the freezer compartment to cool the frozen items.

A first baffle is located in the fan panel between the return air grill and the fan and a second baffle is located in the fan panel between the rear duct and the evaporator. The baffles are made of a lightweight and flexible material and are moveable between a flexed position and a vertical non-flexed position.

During normal operation, the airflow created by the fan deflects the baffles to the flexed position to allow the air to flow through the fan panel unhindered. Moisture on the fins of the evaporator can form frost and ice that increases resistance to the airflow through the evaporator.

A defrost mode is performed to melt the ice and frost. The fan is turned off and a heater is activated to melt the ice and frost. When the fan is turned off, the baffles drop to a vertical, straight position due to gravity. The vertical baffles create resistance in the airflow and prevent heat and moisture generated by the heater from entering the freezer compartment and forming frost on the frozen items.

After defrosting is complete, the heater is then turned off and the fan is activated to again cool the freezer compartment. The force of the airflow created by the fan deflects the baffles to the flexed position, allowing the air to flow through the fan panel without any resistance.

These and other features of the present invention will be best understood from the following specification and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The various features and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawing that accompany the detailed description can be briefly described as follows:

FIG. 1 schematically illustrates the reach-in glass door freezer of the present invention;

FIG. 2 schematically illustrates the fan panel of the freezer during normal operation;

FIG. 3 schematically illustrates the fan panel of the freezer during a defrost mode;

FIG. 4 schematically illustrates a second embodiment of the baffles of the present invention during normal operation; and

FIG. 5 schematically illustrates the second embodiment of the baffles of the present invention during a defrost mode.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 illustrates an example reach-in glass door freezer 10. A glass door 12 is pivotally attached to the freezer 10 by a hinge 14 and is moveable between an open position and a closed position. The freezer 10 defines a freezer compartment 16 that stores and freezes frozen items 18, such as food. The frozen items 18 are stacked on shelves 20 in the freezer compartment 16.

When a shopper wants to obtain one of the frozen items 18, the shopper pivots the door 12 to the open position and obtains the desired frozen item 18. The shopper then closes the door 12 to maintain the cool air in the freezer compartment 16.

As further shown in FIGS. 2 and 3, the freezer 10 further includes a fan panel 22. Warm and humid air from the freezer compartment 16 enters the fan panel 22 through a return air grill 24. A fan 26 draws the air inside the fan panel 22 through an evaporator 28 for cooling. In the evaporator 28, the warmed air from the freezer compartment 16 exchanges heat with the exterior air, cooling the air in the evaporator 28 to between approximately −10°and −20°F. The cooled air then exits the fan panel 22 through a rear duct 30 and reenters the freezer compartment 16 to cool the frozen items 18.

A first baffle 32 and a second baffle 34 are located in the fan panel 22 to prevent moisture from entering the freezer compartment 16 during a defrost mode. The first baffle 32 is located between the fan 26 and the return air grill 24 and a second baffle 34 is located between the evaporator 28 and the rear duct 30. The baffles 32 and 34 are made of a lightweight and flexible material and are moveable between a flexed position during normal operation (shown in FIG. 2) and a vertical, non-flexed, straight position during the defrost mode (as shown in FIG. 3).

FIG. 2 illustrates the baffles 32 and 34 during normal operation. The airflow created by the fan 26 deflects the baffles 32 and 34 to the flexed position. Because the baffles 32 and 34 are deflected, the air flowing through the fan panel 22 can flow unhindered, reducing the pressure drop in the airflow and preventing misdistribution of the airflow. That is, since the baffles 32 and 34 are not straight and vertical, they do not interrupt the airflow.

During normal operation, moisture on the fins 42 of the evaporator 28 can freeze to form frost and ice. As the amount of frost and ice on the fins 42 of the evaporator 28 increases, the gap between the fins 42 decreases and increases resistance to the airflow through the evaporator 28. A defrost mode is performed to defrost and melt the frost and ice formed on the fins 42 of the evaporator 28 and decrease resistance of the airflow through the evaporator 28.

In one example, a defrost mode is initiated when a defrosting sensor 44 detects a condition that necessitates defrosting. For example, defrosting is needed when the defrosting sensor 44 detects frost and ice on the fins 42 of the evaporator 28.

FIG. 3 illustrates the fan panel 22 when the freezer 10 is operating in the defrost mode. During the defrost mode, the fan 26 is off and a heater 38 in the fan panel is activated. The fan 26 does not create an airflow when the fan 26 is off, and the baffles 32 and 34 drop to a straight vertical position due to gravity. In the vertical position, the baffles 32 and 34 create resistance in the airflow and prevent heat and moisture generated by the heater 38 from exiting the rear duct 30 and the return air grill 24 of the fan panel 22 and entering the freezer compartment 16. By preventing the escape of moisture and fog into the freezer compartment 16, the development of frost on the frozen items 18 is minimized. The water that melts from the fins 42 of the evaporator 28 falls to a drain pan 40 and drains towards the front the freezer 10.

After defrosting is complete, the heater 38 is turned off and the fan 26 is activated to again cool the air in the freezer compartment 16. When the fan 26 is activated, the force of the airflow generated by the fan 26 deflects the baffles 32 and 34 to the flexed position shown in FIG. 2, allowing air to flow through the fan panel 22 without any resistance.

FIG. 4 schematically illustrates an alternative baffle 132 including a plurality of baffle segments 134. A portion 136 of each baffle segment 134 is attached to a vertical support 138. When the fan 26 is activated, the baffle segments 134 pivot to the position shown in FIG. 4. In this position, the air can flow uninterrupted between the baffle segments 134 and through the fan panel 22. When the fan 26 is turned off during a defrost mode, the baffle segments 134 drop and become substantially vertical to prevent moisture from entering the freezer compartment 16. As shown exaggerated in FIG. 5, each baffle segment 134 has a length such that the baffles segments 134 overlap when in the non-flexed position. By employing baffles segments 134, the amount of noise generated by the baffle 132 is reduced.

The foregoing description is only exemplary of the principles of the invention. Many modifications and variations of the present invention are possible in light of the above teachings. The preferred embodiments of this invention have been disclosed, however, so that one of ordinary skill in the art would recognize that certain modifications would come within the scope of this invention. It is, therefore, to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described. For that reason the following claims should be studied to determine the true scope and content of this invention. 

1. A freezer comprising: a fan chamber; a fan in said fan chamber that draws air into said fan chamber; and at least one flexible baffle in said fan chamber moveable between a flexed position when said fan is active and a non-flexed position when said fan is inactive.
 2. The freezer as recited in claim 1 further including a door pivotally attached to the freezer between an open position and a closed position.
 3. The freezer as recited in claim 1 further including a freezer chamber and an evaporator in said fan chamber and said fan draws said air into said evaporator, and wherein said air flowing through said evaporator rejects heat to a fluid medium, and said air cooled in said evaporator is provided to said freezer chamber.
 4. The freezer as recited in claim 3 wherein said fan chamber includes an inlet and an outlet, and said at least one baffle comprises a first baffle and a second baffle, and said first baffle is located between said inlet and said fan and said second baffle is located between said evaporator and said outlet.
 5. The freezer as recited in claim 3 wherein said fluid medium is air.
 6. The freezer as recited in claim 3 further including a heater, and wherein said heater operates to generate heat when said fan is inactive.
 7. The freezer as recited in claim 6 wherein said at least one baffle is in said straight position when said heater operates to prevent moisture from entering said freezer chamber from said fan chamber.
 8. The freezer as recited in claim 6 further including a defrost sensor, and said heater operates to generate heat when said defrost sensor detects a defrosting condition of said evaporator.
 9. The freezer as recited in claim 8 wherein said defrosting condition is frost on said evaporator.
 10. The freezer as recited in claim 1 wherein said fan creates an airflow when active, and said airflow deflects said at least one baffle to said flexed position.
 11. The freezer as recited in claim 1 wherein said at least one baffle is in said straight position when said fan is inactive due to gravity.
 12. The freezer as recited in claim 1 wherein said at least one baffle includes a plurality of baffle segments attached to a baffle structure, and said plurality of baffle segments are pivotable between said flexed position and said non-flexed position.
 13. A freezer comprising: a freezer chamber; a fan chamber having an inlet and an outlet; a fan in said fan chamber that draws air into said inlet of said fan chamber; an evaporator in said fan chamber and said fan draws said air into said evaporator, and wherein said air flowing through said evaporator rejects heat to a fluid medium, and said air cooled in said evaporator exits said fan chamber through said outlet and is provided to said freezer chamber; and a heater that operates when said fan is inactive; and at least one flexible baffle in said fan chamber moveable between a flexed position when said fan is active and a non-flexed position when said fan is inactive.
 14. The freezer as recited in claim 13 further including a heater that operates to generate heat when said fan is inactive.
 15. A method of controlling an airflow comprising the steps of: activating a fan to deflect at least one baffle to a flexed position; sensing a defrosting condition; and deactivating the fan when the step of sensing detects the defrosting condition to undeflect the at least one baffle to a non-flexed position.
 16. The method as recited in claim 15 further including the step of cooling air in an evaporator, and the step of sensing includes sensing a defrosting condition of the evaporator. 